RF (radio frequency) data communications can be implemented by using various frequency bands. One example for low-power, short-distance bidirectional communications is UWB communication systems which utilizes UWB radio transmission (e.g., 3.1-10.6 GHz). Such a UWB communication system is used to establish wireless data link between a parent machine and a child machine. An example of UWB communications is described in Japanese Laid-open Patent Publication Tokukai 2005-129993.
In view of the above, it would be desirable to provide improved UWB communication systems which are capable of providing the user of the system with information relating to communication environments.